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Development of a 3-Dimensional Placenta-on-a-Chip Platform for Pre-eclampsia Study
Seorin Jeong(정서린),Tae-Joon Jeon(전태준),Sun Min Kim(김선민) 대한기계학회 2021 대한기계학회 춘추학술대회 Vol.2021 No.11
The placenta is an organ that occurs only temporarily during pregnancy and connects the fetus and the mother for exchange materials. As a fetus grows, more and more material exchange is required and, so spiral artery remodeling through trophoblast invasion must be properly performed in the initial pregnancy stage. If this process does not well carry out, it can lead to the abnormal placental development and pre-eclampsia. In this study, we developed an in vitro placenta-on-a-chip which can mimic the microenvironment of the placenta and showed the effect of trophoblast invasion. The 3-dimensional vascular structure was reproduced using Collagen type-1 and Human Umbilical Vein Endothelial Cells (HUVECs). The vascular function was confirmed by immunofluorescence assay. Co-culture of HUVECs and trophoblast in 3% hypoxic environment promotes trophoblast invasion and induces changes in vascular structure. This platform is applicable to placenta related studies including drug screening and toxicity test.
Wen, Xianyu,Jeong, Seorin,Kim, Younghoon,Bae, Jeong Mo,Cho, Nam Yun,Kim, Jung Ho,Kang, Gyeong Hoon BioMed Central 2017 CLINICAL EPIGENETICS Vol.9 No.-
<P><B>Background</B></P><P>Formalin-fixed, paraffin-embedded (FFPE) tissues are important resources for profiling DNA methylation changes and for studying a variety of diseases. However, formalin fixation introduces inter-strand crosslinking, which might cause incomplete bisulfite conversion of unmethylated cytosines, which might lead to falsely elevated measurements of methylation levels in pyrosequencing assays. Long interspersed nucleotide element-1 (LINE-1) is a major constituent of repetitive transposable DNA elements, and its methylation is referred to correlates with global DNA methylation. To identify whether formalin fixation might impact the measured values of methylation in LINE-1 repetitive elements and whether prolonged heat-induced denaturation of DNA might reduce the artificial increases in measured values caused by formalin fixation, we analyzed paired fresh-frozen (FF) and FFPE xenograft tissue samples for their methylation levels in LINE-1 using a pyrosequencing assay. To further confirm the effect of a heating step in the measurement of LINE-1 or single gene methylation levels, we analyzed FFPE tissue samples of gastric cancer and colorectal cancer for their methylation status in LINE-1 and eight single genes, respectively.</P><P><B>Results</B></P><P>Formalin fixation led to an increase in the measured values of LINE-1 methylation regardless of the duration of fixation. Prolonged heating of the DNA at 95 °C for 30 min before bisulfite conversion was found (1) to decrease the discrepancy in the measured values between the paired FF and FFPE tissue samples, (2) to decrease the standard deviation of the measured value of LINE-1 methylation levels in FFPE tissue samples of gastric cancer, and (3) to improve the performance in the measurement of single gene methylation levels in FFPE tissue samples of colorectal cancer.</P><P><B>Conclusions</B></P><P>Formalin fixation leads to artificial increases in the measured values of LINE-1 methylation, and the application of prolonged heating of DNA samples decreases the discrepancy in the measured values of LINE-1 methylation between paired FF and FFPE tissue samples. The application of prolonged heating of DNA samples improves bisulfite conversion-based measurement of LINE-1 or single gene methylation levels in FFPE tissue samples.</P><P><B>Electronic supplementary material</B></P><P>The online version of this article (doi:10.1186/s13148-016-0308-0) contains supplementary material, which is available to authorized users.</P>
( Dong-hae Lee ),( Jong-hun Ha ),( Jeong-ih Shin ),( Kyu-min Kim ),( Jeong-gyu Choi ),( Seorin Park ),( Jin-sik Park ),( Ji-hyeun Seo ),( Ji-shook Park ),( Min-kyoung Shin ),( Seung-chul Baik ),( Woo- 한국미생물생명공학회(구 한국산업미생물학회) 2021 Journal of microbiology and biotechnology Vol.31 No.3
Two virulence factors of Helicobacter pylori, cagA and vacA, have been known to play a role in the development of severe gastric symptoms. However, they are not always associated with peptic ulcer or gastric cancer. To predict the disease outcome more accurately, it is necessary to understand the risk of severe symptoms linked to other virulence factors. Several other virulence factors of H. pylori have also been reported to be associated with disease outcomes, although there are many controversial descriptions. H. pylori isolates from Koreans may be useful in evaluating the relevance of other virulence factors to clinical symptoms of gastric diseases because the majority of Koreans are infected by toxigenic strains of H. pylori bearing cagA and vacA. In this study, a total of 116 H. pylori strains from Korean patients with chronic gastritis, peptic ulcers, and gastric cancers were genotyped. The presence of virulence factors vacAs1c, alpA, babA2, hopZ, and the extremely strong vacuolating toxin was found to contribute significantly to the development of severe gastric symptoms. The genotype combination vacAs1c/alpA/babA2 was the most predictable determinant for the development of severe symptoms, and the presence of babA2 was found to be the most critical factor. This study provides important information on the virulence factors that contribute to the development of severe gastric symptoms and will assist in predicting clinical disease outcomes due to H. pylori infection.